1. Field of the Invention
The present invention relates to a headrest support which supports a headrest of a seat of various transport means (vehicle, airplane, vessel and the like), and more particularly to a headrest support which can support a headrest which is mounted on the transport means by way of a receiving member and/or a headrest stay by completely eliminating a play of the headrest (setting the play to approximately zero) and a locking member which is assembled to the headrest support.
2. Description of the Related Art
With respect to this type of transport means, particularly with respect to the vehicle, along with the lapse of time, demands for the safety, the comfortable ride, the easiness of manipulation or driving and the like have been changed and hence, various improvements have been made to meet the demands. With such improvements, it is possible to enhance the safety, the comfortable ride, the tranquility or the functionality of the vehicle. Further, recently, due to the enhancement of the hermetic property of the vehicle, there has been a particular demand for the tranquility in the interior of the vehicle. To ensure the safety, the comfortable ride, the tranquility and the like, it is necessary to eliminate rattling sounds which are generated in the headrest and in the vicinity of the headrest. The rattling sounds are generated due to the presence of a fitting gap between a stay of the headrest which supports the headrest (hereinafter referred to simply as “stay”) and a headrest support which supports the stay in a state that the stay is inserted (supported by fitting) into the headrest and/or an insertion supporting (fitting) gap (play, clearance or the like) which is formed between the headrest support and a square-pipe-shaped receiving member (support receiving member) which is fixedly secured to a seat, and the vibration at the time of traveling. Accordingly, the rattling sounds are increased depending on kinds of vehicles and/or the high-speed traveling, the rough road or the like thus giving rise to the deterioration of the comfortable ride. In view of the above-mentioned situation, the elimination of the rattling sounds constitutes an urgent task to be solved.
Japanese Utility Model Laid-open He12(1990)-23842 (prior literature 1) discloses the related structure for preventing rattling sounds. That is, the literature 1 discloses “the support structure of a headrest stay”. To summarize the structure, resilient projecting members are mounted on a holder portion which includes through holes allowing the fitting of stays, and the holder portion is brought into pressure contact with the bracket by making use of the resilient projecting members whereby the hermetic property is ensured and, at the same time, the stays are resiliently supported by way of the slits formed in the holder portion. This structure is characterized in that with the use of the resilient projecting members and/or the slits, a gap between the stays and the holder portion and a gap between the bracket and the holder portion are respectively eliminated thus achieving the prevention of the rattling sounds and the reduction of the friction resistance to the holder portion which is generated when the stays are moved upwardly and downwardly.
Here, inventors of the present invention have already proposed the epoch-making headrest support and/or the structure as means for overcoming such rattling sounds and these headrest support and/or the structure have satisfied the demands of the market. Further, the headrest support and/or the structure are already mounted on various vehicles in Japan and foreign countries. Japanese Patent 3475320 (prior literature 2) discloses such headrest support and/or the structure. That is, the literature 2 is directed to “a headrest support”. To summarize the headrest support, the headrest support holds stays of a headrest arranged above a seat by fitting and is supported on a receiving member arranged on the seat. The headrest support has a head portion, a neck portion and a barrel portion which are integrally formed. Through holes which allow the fitting of the stays therein are formed in the headrest support. Stay pressing portions which resiliently hold the stays inwardly by way of cut grooves are formed in the barrel portion. Tongue portions which can be biased downwardly are formed in the neck portion and bias the receiving means downwardly. Removal-prevention bulging portions which support a lower surface of the receiving member are formed on the barrel portion in a state that the removal-prevention bulging portions are arranged to face the tongue portions. Here, the tongue portions and/or the removal-prevention bulging portions are provided for preventing the removal of the headrest support and the generation of plays, while the stay pressing portions are provided for preventing the generation of plays by pressing the stays. Due to such constitution, the headrest support can obtain following advantages.
(A) It is possible to insert the stays without being influenced by the irregularities of tolerances of respective portions or the irregularities of tolerances attributed to temperature change and hence, it is possible to assemble the headrest with no play in a fitting state of the stays and the headrest support.
(B) When the stays are inserted into the headrest support, the projecting portions formed on the inner peripheral surface of the stay pressing portion are resiliently outwardly biased due to the stays and hence, it is possible to insert the stays with a reasonable load.
(C) It is possible to eliminate rattling sounds between the stays and the headrest support and between the headrest support and the support receiving member (receiving member).
(D) It is possible to realize the driving of a vehicle while ensuring the comfortable ride and the tranquility.
Further, since the headrest support is integrally formed, the manufacturing cost can be reduced.
However, to consider a current situation where the above-mentioned substantially complete elimination of the rattling sounds is strongly desired, it is desirable to achieve the further improvement of the above-mentioned headrest support and/or the structure.